Based on previous work and proof of the principle that each person possesses a unique average level and regulatory control of variation of blood constituents describing his primary health, a research plan is proposed to study the chronological changes in 3000 healthy people. Continued development of improved automated testing and of a data processing system of maximum precision and efficiency, will permit the documentation of individual blood profiles characteristic of different life habits, occupations, aging and effects of pollutants. Periodic updating of profiles will reveal the predictive significance of individual deviations and the value of rational programs for monitoring good health. New tests will be evaluated for their use in health monitoring. Correlation and profile modeling programs will be devised for analyzing the voluminous data. Precise monitoring of individual health will reveal the degree of physiological regulation, the causes of failure of regulation and the reversability of deviations from the person's baseline reference health profile. Such information will support the concept of health maintenance and contribute to preventive medicine and will be of great educational value. Wide application to health surveillance and to preventive medical management can reduce sick time and medical costs and contribute substantially to improved individual productivity, creativity and prolonged useful and enjoyable life.